Investigation begins after fatal Spitfire crash

It could take several weeks to determine the cause of a fatal plane crash during an air show in Adelaide's north, the Australian Transport Safety Bureau (ATSB) says.

Experienced pilot Roger Stokes, 73, was killed when his homemade replica Spitfire crashed close to homes at Salisbury on Sunday afternoon during a demonstration flight above nearby Parafield Airport.

Mr Stokes, from Monarto east of Adelaide, was taking part in the Antique and Classic Aircraft Display.

Hundreds of spectators were at the event and witnesses saw his plane nose-dive and disappear from view.

The aircraft crashed into a fence between two businesses on Frost Road in Salisbury about 2:00pm (ACST), narrowly missing a busy soccer pitch and homes.

Local resident Anne Gibbons was just 50 metres from the point of impact and said it sounded like the engine stalled.

"Before when it was up high you could hear it but the moment just before it disappeared from my roof you couldn't hear anything," she said.

"It was like silent and then there was just that sudden explosion."

The wreckage remains at the scene of the accident as ATSB engineers analyse it for clues.

Lead investigator Richard Davies says determining the cause will take at least several weeks.

"Quite often with light aircraft accidents, because they don't have sophisticated recording mediums like large passenger aircraft, we're very reliant on the physical evidence on site and the reporting of witness observations," he said.

"We've taken a lot of photographs. We've only just started to work on the wreckage and we have to take a very close look at it.